The Republican. [volume] (Oakland, Md.) 1877-current, 1887-07-30
SCIENCE AND INDUSTRY,

ivy llllllOh SftI DOuo WtIt u1dnus
featured last year for use by electric
light companies.
DO not lubricate an oxygen pump
with oil, but with soapsuds or some
thing that will not burn in oxygen.
-Fifty-fve million cans were used
in this country last year for canning
tomatoes, and as many as 100000, 900
cans were used for other vegetables.
By careful experiments, NJ Bloch
has determined that it takes 1-72 of q
second longer to hear sound than to
see sight, and 1-21 of second longer
to feel touch than to see sight
ArkGnsaw Traveller.
Although there are 1000 less tan
neries in this country than there were
twelve years ago, the aggregate of
leather produced is much greater, ow-
ing to the increased capacity of the
larger ones which remained in opera
ton, and many large ones annually
erected add their product.
1t has heretofore been supposed
that the implements of jade found in
British Columbia and elsewhere on the
Pacific coast must be of Asatic origin,
as the mineral was not known to exist
in Western America; but boulders of
jade have now been discovered in the
valley of the Frazer river, and jade
also occurs in Alaska.-M Y. Ledger.
Judge Macarthur thinks that the
rules of trades organizations which
limit the number of boys who may be
received at apprenticeship. though in
tended for good, actually do great
harm to American industries. They
exclude Americans from the trades,
and make us dependent upon foreign
ers who come here with their trades al
ready learned. Public Opinion.
A Glasgow engineering firm have
constructed what is said to be the larg-
est planning machine in the world,
specially intended and designed to be
employed in connection with the prep
aration of steel plates for the Orders of
a railway bridge in New South Wales.
The weight Of this vast machine is
stated to be some thirty-five tons, and
it is capable of planning the edge of a
plate thirty-eight feet in length by five
feet wide.
AN English physicist has, it is
said, made a perfect pendulum by sus-
pending lead shot by single fiber of
cocoon silk in a vacuum produced by a
Sprengel pump. The shot, one-six-
teenth of an inch in diameter, weighs
one-third of a gram, is suspended by a
two-foot fiber, and is placed in a tube
three-quarters of an inch internal di-
ameter. 1t has vibrational range of
quarter of an inch on each side of mid
position, the vacuum being equivalent
to one-tenth of millionth of an at
mosphere. Boston Budget
The extreme delicacy of the sense
of smell is illustrated in a recent ex-
pertinent with mercaptan. liquid Of
extremely offensive odor. 1t was
found that 1-460, 000,0 900 of a milli-
gramme was detachable, quantity $50
times less than the minimum of sodium
recognizable by the spectroscope. Il
is not every olfactory nerve, however,
that can detect so minute quantity
Some unfortunate (or fortunately peo-
pie seem unable to smell any thing. -
N. T. Examiner.
AT the recent reception of the Royal
Society of London, Mr.. C. V. Boys ex-
hibited the actual working of the appa-
ratus which he has devised for the pur-
pose of drawing out glass, minerals and
metals, when heated, into extremely
fine wire or thread. The Aheneuni
says: "A thin rod of the material was
fastened to the tail of an arrow and
heated at the end of an oxhydrogen
flame. The trig ger of cross-bow was
then pulled and the arrow shot. In
this way, quartz can be drawn so fine
that the thinnest parts are beyond the
power of any microscope to define
Them